A novel TAL1/miR-149* axis accelerates tumor growth of human T cell acute lymphoblastic leukemia.

Herein, we aimed to investigate the roles of TAL1 and miR-149* in T cell acute lymphoblastic leukemia (T-ALL). The biological characteristics, including cell proliferation, cell apoptosis, and cell cycle, were analyzed in Molt4 cells. ChIP results revealed that miR-149* expression in Jurkat cells transfected with overexpression TAL1 plasmid was higher than that in Jurkat cells alone, while miR-149* expression in Molt-4 cells transfected with knockdown TAL1 plasmid was lower than that in Molt-4 cells alone, suggesting that TAL1 might direct target miR-149*. This was further confirmed by a luciferase activity report assay. Finally, biological functions, such as cell proliferation, cell cycle, and apoptosis of TAL1 and miR-149* were measured by MTT and flow cytometry, respectively. It was uncovered that enhanced TAL1 and miR-149* expression promoted cell proliferation, induced cell cycle arrest in G0/G1 phase, and inhibited apoptosis in Molt-4 cells. In contrast, decreased TAL1 and miR-149* expression suppressed cell proliferation, abolished cell cycle arrest in G0/G1 phase, and accelerated apoptosis in Molt-4 cells. Thus, these data indicate that TAL1 directly regulates miR-149* expression and TAL1/miR-149* link is implicated in the pathogenesis of T-ALL.